GB2540362A

GB2540362A - Temperature sensor arrangement

Info

Publication number: GB2540362A
Application number: GB1512229.4A
Authority: GB
Inventors: Robinson Derya; Richard Gough Keith; Mulcahy John
Original assignee: British Gas Trading Ltd
Current assignee: British Gas Trading Ltd
Priority date: 2015-07-13
Filing date: 2015-07-13
Publication date: 2017-01-18
Anticipated expiration: 2035-07-13
Also published as: GB201512229D0; WO2017009630A1; GB2540362B

Abstract

A housing 100 for an environmental control or sensor device 10 comprises a front face 102 with a display or control element 110 and a rear face 104 suitable for wall mounting. One or more side walls 106 join the front face102 to the rear face 104. The housing 100 contains powered electronic components, such as a microprocessor, which generate heat. A temperature sensing element 124 is located in an air flow path 122 between an inlet and outlet 112 spaced apart on the housing 100. A baffle 120 defines the air flow path 122 and separates the heat generating components from the temperature sensor 124. The inlets and outlets 112 may comprise a plurality of apertures. Both the powered electrical components and the temperature sensor 124 may be mounted on a circuit board 116 and the housing 100 may comprise battery compartments 118. The baffle 120 may comprise a heat reflective coating/material and extend between two side walls 106 of the housing to seal the electronic components in the housing 100 to protect against the ingress of fluid from the inlet or outlet 112. The baffle may comprise two non-coaxial curves (220-1,220-2, Fig. 7).

Description

Temperature sensor arrangement

The invention relates to environmental control and/or sensor devices. In particular, the invention relates to a housing for such a device, and the arrangement of a temperature sensing element within the housing.

For a long time central heating systems have been controlled using simple thermostat devices, which are typically located remotely from a central heating boiler and connected via a wired connection. Such devices provide basic functionality for controlling the temperature in an environment and, for very simple thermostat devices, have no power requirement.

Recently, the ability to control central heating systems has become more advanced. Environmental control and/or sensor devices, which include a temperature sensor for detecting the temperature of its surroundings and related control components, have been developed to provide more flexible control over central heating systems. Some of these devices are wirelessly connected to the central heating boiler, which affords greater flexibility in where the device can be positioned. Furthermore, some devices have remote control capability, for example using an application on a tablet computer or smartphone.

To provide the enhanced functionality, devices may now be battery-powered or wired into the main electrical supply. With such devices, however, the powered electronic components and/or the batteries housed in the device generate heat during use. A disadvantage of this generated heat is that it may influence the readings obtained by the temperature sensor also located in the housing such that a true temperature of the surrounding ambient air may not be obtained.

According to the present invention there is provided a housing for a powered environmental control and/or sensor device, the housing comprising: a front face including a display or control element; a rear face for mounting to a wall; one or more side walls arranged between the front face and the rear face; one or more powered electronic components including heat generating components; a temperature sensing element; and a baffle defining an air flow path that is arranged to allow external ambient air to pass through a portion of the housing from an inlet to an outlet spaced apart on the one or more side walls of the housing, wherein the temperature sensing element is located in the air flow path so as to be substantially separated from the heat generating components of the powered electronic components by the baffle.

By arranging the air flow path to be substantially separate from the heat generating components, the temperature sensing element is primarily responsive to the temperature of ambient air due to the baffle acting to deflect heat generated by the heat generating components.

The housing may be substantially rectangular. The air flow path may extend between two different side walls of the housing, preferably wherein one of the side walls is an upper or lower side wall. The side walls may be adjacent. The corners between the two adjacent side walls may be generally curved.

The side walls may have a depth of at least about 1cm, preferably at least about 1,75cm, and more preferably at least about 2.5cm to provide the housing with sufficient interior space for electronic components and increased air flow.

The inlet and/or outlet may comprise a plurality of apertures in the (or each) side wall. The inlet and/or outlet preferably comprise(s) at least five apertures. The apertures may be generally circular holes, each preferably having a diameter of between about 1mm and about 3mm, and preferably having a diameter of about 2mm. The apertures provided on a side wall may have a total area (where total area = sum of the individual aperture areas) of between about 0.05cm2 and about 0.7cm2, preferably between about 0.1cm2 and about 0.5cm2, and more preferably between about 0.15cm2 and about 0.3cm2. Even more preferably, the apertures provided on a side wall may have a total area of at least about 0.5cm2.

By arranging the inlet and/or outlet as a plurality of discrete apertures, large particles of airborne matter and/or creatures can be prevented from entering the air flow path, while ensuring that a sufficient flow of ambient air is able to enter the air flow path to allow the temperature of the ambient air to be sensed by the temperature sensing element.

The apertures may be arranged on the side wall such that the closest aperture to the rear face of the housing is spaced at least about 1cm from the rear face of the housing, such that ambient air entering the housing is not influenced by the temperature of a wall onto which the housing is mounted. A vertical separation may be provided between the inlet and outlet so as to promote natural convection of external ambient air along the air flow path. The vertical separation may be at least about 0.8cm, preferably at least about 1cm, and more preferably at least about 1,2cm.

The air flow path may have an average cross sectional area of at least about 0.75cm2, preferably about 1cm2, and more preferably at least about 1.25cm2, to ensure that the ambient air can flow freely along the airflow path with minimal restriction.

While the average power dissipated by the heat generating components may be low, for example typically less than 1mW, high power dissipation may occur at certain times when the powered electronic components are in operation. At such times, the heat generating components may dissipate at least about 100mW of power during use, and may exceed power dissipation of 500mW for short periods, for example if the powered electronic components include a display backlight and a radio transmitter/receiver components, and the backlight is turned on during radio communications.

The baffle is preferably arranged to provide a barrier that substantially deflects radiant and/or direct heat generated by the heat generating components and thereby substantially shields the temperature sensing element such that it is primarily responsive to the temperature of ambient air. The temperature sensing element is preferably an electronic temperature sensor. The baffle may comprise a suitable heat reflective material and/or coating arranged to provide a barrier to radiant and/or direct heat. The baffle preferably has a thickness of at least about 1mm. The baffle is preferably a substantially straight member but, if necessary, may alternatively be substantially defined by two non-coaxial arcs (or curves), to provide an airflow path that optimises the number of apertures available in the side wall(s) of the housing and hence the overall surface area of the inlet and/or outlet. A baffle may be arranged to partition the air flow path from the heat generating components by providing a complete partition (or barrier) between the heat generating components and the air flow path, should the heat generated be such that it would substantially affect the temperature sensing element and/or the temperature of the ambient air flowing in the air flow path. Alternatively, the baffle may be arranged as an incomplete partition (or barrier), and the aim of the invention still be met, if the heat generated by the heat generating components was of a temperature that would not substantially affect the temperature sensing element and/or the temperature of the ambient air, or at least if the heat was such that an incomplete partition baffle could deflect it away from the airflow path sufficiently.

The baffle may further be arranged to seal the powered electronic components within the housing such that they are substantially protected against the ingress of fluid through the inlet and/or outlet.

Furthermore, the arrangement of the air flow path, and/or the inlet and/or outlet, in the side wall is preferably such that ambient air flowing along the air flow path and across the temperature sensing element is replenished at such a rate that there is insufficient time for it to be substantially heated by the heat generating components. In addition, a partial (or “perforated”) baffle may be arranged such that it provides an air flow path and also delivers (or directs) ambient air through the housing such that it can cool the heat generating components, while still performing its intended function of deflecting heat. A circuit board, onto which the powered electronic components may be mounted, may be arranged to extend into the air flow path, wherein the temperature sensing element may (also) be mounted onto the circuit board within the air flow path, to provide a compact housing with efficiently packaged electronic components. The circuit board is preferably arranged such that the baffle extends higher than the temperature sensing element in the housing. In other words, the baffle may extend further towards the rear face of the housing, and may even be in contact with it.

The housing may further comprise a battery compartment, so that external power source is not required for the electronic components. A digital electronic microprocessor for controlling the powered electronic components may also be provided, to enable digital control of a central heating system, for example.

According to another aspect of the invention there is also provided a housing for a powered environmental control and/or sensor device, the housing being substantially rectangular and comprising: a front face including a display and/or control element; a rear face for mounting to a wall; side walls arranged between the front face and the rear face, including an upper side wall and an opposing lower side wall, and two opposing side walls; a baffle defining an airflow path that is arranged to allow external ambient air to pass through a portion of the housing, wherein the air flow path extends between an inlet and an outlet spaced apart on the housing, wherein one of the inlet or outlet is provided on one of the upper or lower side walls and the other of the outlet or inlet is provided on another side wall, and wherein the inlet and outlet each comprise a plurality of apertures arranged to allow external ambient air to enter the housing; one or more powered electronic components including a digital electronic microprocessor and other heat generating components; and a temperature sensing element located in the air flow path so as to be substantially separated from the heat generating components of the powered electronic components by the baffle.

According to another aspect of the invention there is also provided a powered environmental control and/or sensor device comprising a housing as described herein.

According to another aspect of the invention there is also provided a housing substantially as described herein with reference to the accompanying drawings.

As referred to herein, the terms “rectangular” and “substantially rectangular” are intended to encompass square shapes, and include shapes having rounded corners.

As referred to herein, the term “front face” preferably connotes a user-facing face of the housing, which is typically substantially parallel to the support surface (e.g. a wall) on which the device is mounted.

As referred to herein, the term “rear face” preferably connotes a face of the housing that is orientated away from a user, and which may therefore be suitable for mounting to a wall or other structural feature.

As referred to herein, the term “side face”, “side wall” or the like preferably connotes an exterior surface of the housing that joins (typically orthogonally) a rear face of the housing and a (user-facing) front face. A substantially rectangular housing would then have four side walls, but other shaped designs may have different numbers of side walls (e.g. a single circular side wall for a round shape).

As referred to herein, the term “baffle” preferably connotes a wall, barrier or other feature that restrains the flow of ambient air along a desired air flow path. The baffle may have further properties, such as to shield the ambient air from heat sources in the housing, for example.

As referred to herein, the term “separated” (in the context of the temperature sensing element) preferably connotes arranging the temperature sensing element within the air flow path to be apart from the heat generating components in the housing, in particular such that the temperature sensing element is primarily responsive to the temperature of ambient air.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

An example of the present invention will now be described with reference to the accompanying figures, in which:

Figure 1 shows an exemplary housing for an environmental control and/or sensor device;

Figure 2 shows a side wall of the housing having a plurality of apertures;

Figure 3 shows a lower side wall of the housing having a plurality of apertures;

Figure 4 shows a rear view of a housing with a temperature sensing element arranged according to a first exemplary embodiment;

Figure 5 shows an enlarged view of a part of the housing of Figure 4;

Figure 6 shows a rear view of a housing with a temperature sensing element arranged according to a second exemplary embodiment; and

Figure 7 shows an enlarged view of a part of the housing of Figure 6.

Figure 1 shows an example of a powered environmental control and/or sensor device 10, which contains powered electronic components (not shown) that typically generate heat during use. The powered electronic components are contained in a housing 100, which is described below as an exemplary embodiment of the present invention.

The housing 100 has a substantially rectangular shape, and includes a front face 102 and a rear face 104, which are maintained in a spaced arrangement by side walls 106 that extend around the periphery of the housing 100. The side walls 106 in this example have a depth of at least 1cm. The rear face 104 of the housing 100 is, preferably, for mounting to a wall, and as such may be provided with suitable attachment elements (not shown).

Control buttons 108 for operating the device 10 are shown provided on an upper (or “top”) side wall 106-1 of the housing 100, although it will be appreciated that control buttons could (also) be provided elsewhere on the housing 100, such as on the side wall 106-2, if necessary. A control element 110 for controlling the device 10 is provided on the front face 102 of the housing 100 in the form of a rotatable knob (or “dial”) 110. Display/indicator elements (not shown) may also be provided.

As also shown in Figure 2, a plurality of apertures 112-1 are provided towards the bottom of the side wall 106-2 of the housing 100. The apertures 112-1 allow ambient air to flow into the housing 100 to where a temperature sensor (not shown) is located. A plurality of similar apertures 112-2 are also provided on a lower (or “bottom”) side wall 106-3 of the housing 100, as shown in Figure 3. In this example, the apertures 112-2 are provided offset from the centre of the lower side wall 106-3, towards the side wall 106-2 of the housing 100.

For the purposes of describing this exemplary housing 100, it may be assumed that the apertures 112-1 on the side wall 106-2 provide an inlet 112-1 to the housing, and the apertures 112-2 on the lower side wall 106-3 provide an outlet 112-2, though it will of course be appreciated that the inlet / outlet may reverse depending on the direction of ambient air flow in/out of the housing 100 and/or natural convention currents in ambient air, for example. The inlet apertures 112-1 and outlet apertures 112-2 are arranged in the housing 100 to be spaced by at least 1cm from the rear face 104 of the housing 100. There is also a vertical separation between the inlet apertures 112-1 and outlet apertures 112-2, of at least about 1cm in this example.

Each plurality of apertures 112-1, 112-2 in this example consists of a substantially regular array of nine substantially circular holes, which extend through the side wall 106-2 and adjacent lower side wall 106-3 of the housing 100, respectively. The apertures 112 could however be of any number and/or size and/or any shape and/or arrangement that allows a sufficient volume of air to enter the housing 100, though apertures 112 in the form of substantially circular holes having a diameter of about 2mm are preferred.

It has been found that having at least five such apertures 112 provides a desirable air flow into the housing 100, though fewer apertures would still allow air to flow, especially if the apertures were of larger diameter. The multiple apertures 112-1, 112-2 in this example are arranged such that each of the inlet and outlet have a total sum area of at least 0.5cm2.

Figure 4 shows inside the rear of the housing 100. As mentioned above, the housing 100 contains powered electronic components, which may include a digital electronic microprocessor, transmitter, receiver, and a display backlight, for example. In the example shown, the powered electronic components (not shown) are hidden behind a back plate 114. A circuit board 116 is provided in the housing 100 for mounting and electrically connecting the powered electronic components. A plurality of battery compartments 118 are provided in the rear face 104 of the housing 100 for providing a power source to the powered electronic components, though an external power supply may be provided in alternative arrangements. A baffle 120 extends between the side wall 106-2 and lower side wall 106-3 to partition a corner of the housing 100 and define an air flow path 122 between the two sets of apertures 112-1, 112-2, which are spaced apart on two adjacent side walls 106-2, 106-3 of the housing 100. The air flow path in this example is arranged to have an average cross-sectional area of at least 1cm2. To enhance its ability to act as a heat barrier, the baffle 120 preferably comprises a heat reflective coating. A temperature sensing element 124 (such as an electronic temperature sensor, or a resistor, for example) is mounted on the circuit board 116 in the airflow path 122. Thus, the air flow path 122 allows ambient air to pass through a portion of the housing 100 that is separated (and, ideally, substantially shielded) from the heat generating components elsewhere in the housing 100. The baffle 120 is, preferably, arranged to extend higher than the temperature sensing element 124.

As can be seen in the enlarged view of the airflow path 122 in Figure 5, the circuit board 116 extends underneath the baffle 120 into the air flow path 122, such that the temperature sensing element 124 can be mounted onto the circuit board 116. A second exemplary embodiment of a housing 200 is shown in Figures 6 and 7, wherein similar features to the first housing 100 are similarly numbered. In this second example, three of the apertures 212-1 provided on the side wall 206-2 of the housing 200 are blocked by part of the battery compartment 218. As a result of this, the baffle 220 is arranged as two curved ‘wall’ portions 220-1, 220-2, which do not share a common centre (i.e. they are not coaxial). The first curved portion of the baffle 220-1 extends inwardly from the remaining unblocked apertures 212-1 on the upper side wall 206-2, and is configured to provide an air flow path that, if extended all the way to the lower side wall 206-3, would encompass a corresponding number of apertures 212-2 on the lower side wall 206-3. The baffle 220 is however modified to include a second curved portion 220-2, which continues from where the first curved portion ends in the air flow path 222. Thus, the baffle 220 is arranged to encompass all nine of the apertures 212-2 on the lower side wall 206-3 of the housing 200, and thereby maximise the volume of air that can flow along the airflow path 222.

In the two exemplary embodiments described above, the baffle 120, 220 is described as a substantially continuous barrier extending between two (different) side walls of the housing 100, 200. The baffle 120, 220 may be further arranged to provide a substantially fluid-tight barrier to prevent any moisture that enters the housing via the inlet or outlet from reaching the powered electrical components.

In an alternative arrangement (not shown), a baffle might be arranged to allow ambient air to enter the housing such that it may cool the heat generating components while still maintaining a sufficient barrier to the generated heat. For example, rather than being continuous, the baffle might have gaps spaced along its length that allow ambient air to pass through while maintaining a substantially (and sufficiently) ‘continuous’ barrier to the heat. Depending on how much power is dissipated, in use, by the heat generating components in the housing, a baffle may only need to extend partially between two side walls while still performing its desired function of deflecting heat.

It will be appreciated that, while the air flow path, and hence the inlet and outlet, are shown in a bottom corner of the housing in the exemplary embodiment of a housing described herein, these features (and hence also the temperature sensing element) could be provided in any comer of a housing, or indeed along the same side wall of a housing, or even an inlet and/or outlet could be provided in the front or rear face, if desired.

The housing may be formed from any suitable material. For example, it may be injection moulded from suitable plastics materials. It will be appreciated that while the housing described above is substantially rectangular, the invention is not limited to this shape and the housing could alternatively be circular, for example or another geometric shape that is suitable for providing a housing.

Thus, it will be understood that the present invention has been described above purely by way of examples, and modification of detail can be made within the scope of the invention.

Claims

1. A housing for a powered environmental control and/or sensor device, the housing comprising: a front face including a display and/or a control element; a rear face for mounting to a wall; one or more side wall(s) arranged to join together the front face and the rear face; one or more powered electronic components, including heat generating components; a temperature sensing element; and a baffle defining an air flow path that is arranged to allow external air to pass through a portion of the housing from an inlet to an outlet spaced apart on the housing, wherein the temperature sensing element is located in the air flow path so as to be substantially separated from the heat generating components of the powered electronic components by the baffle.

2. A housing according to Claim 1, wherein the housing is substantially rectangular.

3. A housing according to Claim 1 or 2, wherein the air flow path extends between two different side walls of the housing, and preferably wherein one of the side walls is an upper side wall or a lower side wall.

4. A housing according to Claim 2 or 3, wherein the two side walls are adjacent, and preferably wherein the join between the two adjacent side walls is a curve.

5. A housing according to any preceding claim, wherein the side walls of the housing have a depth of at least about 1cm.

6. A housing according to any preceding claim, wherein the inlet and/or outlet comprise(s) a plurality of apertures in the (or each) side wall, preferably at least five apertures.

7. A housing according to Claim 6, wherein the apertures are generally circular holes each having a diameter of between about 1mm and about 3mm, and preferably wherein the hole diameters are about 2mm.

8. A housing according to Claim 6 or 7, wherein the plurality of apertures provided on a side wall have a total area of at least about 0.5cm2.

9. A housing according to any preceding claim, wherein the inlet and/or outlet is/are spaced at least 1cm from the rear face of the housing.

10. A housing according to any preceding claim, wherein there is a vertical separation between the inlet and outlet, preferably wherein the vertical separation is at least about 1cm.

11. A housing according to any preceding claim, wherein the air flow path has an average cross-sectional area of at least about 1 cm2.

12. A housing according to any preceding claim, wherein the baffle is arranged to deflect heat generated by the heat generating components, preferably wherein the baffle comprises a heat reflective coating or material.

13. A housing according to any preceding claim, wherein the baffle is substantially defined by two non-coaxial curves arranged to provide an airflow path.

14. A housing according to any preceding claim, wherein the baffle extends between two side walls of the housing.

15. A housing according to any preceding claim, wherein the baffle is arranged to seal the powered electronic components within the housing such that they are substantially protected against the ingress of fluid through the inlet and/or outlet.

16. A housing according to any preceding claim, further comprising a circuit board for mounting one or more powered electrical components, wherein the circuit board is arranged to extend into the air flow path, and wherein the temperature sensing element is mounted on the circuit board within the airflow path.

17. A housing according to Claim 16, wherein the circuit board is arranged such that the baffle extends higher than the temperature sensing element.

18. A housing according to any preceding claim, further comprising one or more battery compartments.

19. A housing according to any preceding claim, further comprising a digital electronic microprocessor for controlling the powered electronic components.

20. A housing for a powered environmental control and/or sensor device, the housing being substantially rectangular and comprising: a front face including a display and/or control element; a rear face for mounting to a wall; side walls arranged between the front face and the rear face, including an upper side wall and an opposing lower side wall, and two opposing side walls; a baffle defining an air flow path that is arranged to allow external ambient air to pass through a portion of the housing, wherein the air flow path extends between an inlet and an outlet spaced apart on the housing, wherein one of the inlet or outlet is provided on one of the upper or lower side walls and the other of the outlet or inlet is provided on another side wall, and wherein the inlet and outlet each comprise a plurality of apertures arranged to allow external ambient air to enter the housing; one or more powered electronic components including a digital electronic microprocessor and other heat generating components; and a temperature sensing element located in the air flow path so as to be substantially separated from the heat generating components of the powered electronic components by the baffle.

21. A powered environmental control and/or sensor device comprising a housing according to any preceding claim.

22. A housing substantially as described herein with reference to and/or as illustrated in the accompanying drawings.